JACKSONVILLE came out a winner in the Super Bowl extravaganza last weekend: Six cruise ships provided about 3,800 extra beds to visitors in town for the event. The Cruise Lines International Association (CLIA) said a total of 7,638 guests would be accommodated on cruise ships during Super Bowl week. Carnival Cruise Lines' Carnival Miracle, Radisson Seven Seas Cruises' Seven Seas Navigator and three vessels from Holland America Line — the Zaandam, the Zuiderdam and the Volendam — were in town as floating hotels. Silversea Cruises' Silver Wind was in Jacksonville under charter